1. Field of the Invention
The invention relates to magnetic card readers for reading data from cards or badges such as employee badges or key cards for electronic locks. The reader "reads" the data from the card, and furnishes the data to a device wherein the data is utilized such as an electronic door lock, a computer, an encoding or a recording device.
2. Description of the Prior Art
U.S. Pat. No. 4,126,780 discloses an optical card reader having a spring to bias the card away from the light detector and a photo-electric bottom detector to produce a signal when the card reaches the bottom of the reader.
U.S. Pat. No. 4,519,228 discloses an electronic recodable lock which includes a magnetic or optical card reader. The card reader includes a lever activated switch which turns on the reading head when the key is inserted into the slot and an end switch which turns the reading head off when the key reaches the end of the slot.
U.S. Pat. No. 3,896,293 discloses a card reader having a constant velocity card transport mechanism. This reader utilizes a cantilever spring to urge a roller which contacts the card toward the read head so that the coded portion of the card will be forced against the read head.
U.S. Pat. No. Re. 29,846 discloses an electronic lock system which includes a key card reader. This card reader contains a micro switch to activate the read sensors after the card has been fully inserted.
U.S. Pat. No. 3,622,991 discloses an electronic locking system which includes an optical card reader system. This card reader utilizes a shutter which is capable of limited pivotal movement to insure correct orientation of the key card in the slot.
None of these patents disclose or suggest the improved card reader of the present invention.
A general problem presented by prior art card readers, such as those described above, includes misreading the data contained on the cards. Such a problem is particularly troublesome for card readers utilized for electronic door locks because the insertion of the correct card key will not result in opening the lock if the data is misread. Misreading may be caused by a misalignment of the card with the read head. In addition, misreading may occur because the card does not move past the read head at a velocity which the read head can accept. Solutions to these problems have been proposed in the art, however, such proposed solutions have proved to be costly to manufacture and maintain.